Overview
Achalasia
1. Clinical Overview
Summary
Achalasia is a primary oesophageal motility disorder characterized by failure of lower oesophageal sphincter (LOS) relaxation and absent oesophageal peristalsis. It results from degeneration of inhibitory neurons in the myenteric plexus. Patients present with progressive dysphagia to both solids and liquids simultaneously, regurgitation of undigested food, and weight loss. High-resolution manometry is the gold standard for diagnosis. Definitive treatment involves disruption of the LOS via pneumatic dilation, surgical myotomy (Heller), or peroral endoscopic myotomy (POEM).
Key Facts
- Definition: Failure of LOS relaxation with absent oesophageal peristalsis
- Incidence: 1 per 100,000 per year
- Peak age: 30-60 years (bimodal distribution)
- Key symptom: Dysphagia to BOTH solids AND liquids (differentiates from mechanical obstruction)
- Diagnostic gold standard: High-resolution manometry
- Treatment gold standard: Heller myotomy or POEM
- Cancer risk: 10-50x increased risk of oesophageal squamous cell carcinoma
Clinical Pearls
Solids AND Liquids: Mechanical obstruction (stricture, cancer) causes dysphagia to solids first, then liquids. Achalasia causes dysphagia to both from the outset because it is a motility disorder.
Bird's Beak: The classic barium swallow appearance shows dilated oesophagus with smooth tapering at the LOS ("bird's beak" or "rat tail" sign).
Pseudoachalasia Warning: In elderly patients with short symptom duration (less than 1 year) and significant weight loss, always exclude malignancy at the gastro-oesophageal junction causing secondary achalasia.
Why This Matters Clinically
Achalasia significantly impairs quality of life through dysphagia, regurgitation, and malnutrition. Delayed diagnosis leads to oesophageal dilation and aspiration risk. The condition is treatable but not curable; all treatments aim to reduce LOS pressure. Long-term surveillance is recommended due to increased oesophageal cancer risk.
2. Epidemiology
Incidence & Prevalence
- Incidence: 1-1.6 per 100,000 per year
- Prevalence: 10 per 100,000
- Trend: Stable or slightly increasing (possibly improved diagnosis)
Demographics
| Factor | Details |
|---|---|
| Age | Bimodal: 30-60 years; can occur at any age |
| Sex | Equal male:female |
| Ethnicity | No significant racial variation |
| Geography | Worldwide; slightly higher in South America (Chagas disease association) |
Risk Factors
Non-Modifiable:
- Genetic predisposition (HLA associations reported)
- Autoimmune diseases (slightly increased in autoimmune conditions)
Associated Conditions:
| Condition | Relationship |
|---|---|
| Chagas disease | Trypanosoma cruzi causes secondary achalasia (endemic in South America) |
| Autoimmune disorders | Associated with Sjögren syndrome, SLE, uveitis |
| Viral infections | HSV, varicella-zoster implicated in neuronal damage |
3. Pathophysiology
Mechanism
Step 1: The Inhibitory Neuron Deficit
- Normal Physiology: LOS tone is a balance between Excitatory (Acetylcholine, Substance P) and Inhibitory (Nitric Oxide, VIP) neurons.
- Pathology: Selective destruction of the Nitric Oxide (NO) synthase-containing inhibitory neurons in the Myenteric Plexus.
- Result: "A Brake Failure". The sphincter cannot relax.
Step 2: The "Chagas" Mimic
- Mechanism in Chagas Disease (South America): Trypanosoma cruzi parasite directly destroys the myenteric plexus neural ganglion cells.
- Result: Identical phenotype to idiopathic achalasia ("Secondary Achalasia").
Step 3: Aperistalsis (The Pump Failure)
- Normal: Swallow induces a coordinated wave of contraction (Peristalsis) to push food down.
- Pathology: As the disease progresses, the excitatory neurons also degenerate (late stage).
- Result: The oesophagus becomes an inert, baggy tube (Mega-oesophagus). Food relies entirely on gravity and hydrostatic pressure (drinking water to force food down).
Step 4: The Pressure Gradient
- Symptom Generation: High LOS pressure + Food Bolus -> Intra-oesophageal pressure rises.
- Regurgitation: When supine, gravity is lost. The retained food flows back up (Regurgitation / Aspiration).
Classification
Chicago Classification v4.0 (High-Resolution Manometry):
| Type | Manometric Features | Treatment Response |
|---|---|---|
| Type I | Absent peristalsis, no pressurization | Moderate |
| Type II | Absent peristalsis WITH pan-oesophageal pressurization | Best (96% response) |
| Type III | Spastic contractions (premature, fragmented) | Poorest (only 70%) |
Anatomical Considerations
- The LOS is normally 2-4cm in length, straddling the diaphragm
- Gastro-oesophageal junction (GOJ) tumours can mimic achalasia (pseudoachalasia)
- Surgical myotomy extends onto gastric cardia to ensure complete LOS division
4. Clinical Presentation
Symptoms
Typical Presentation:
Atypical Presentations:
Signs
Red Flags
[!CAUTION] Red Flags — Consider pseudoachalasia (malignancy) if:
- Age greater than 55 with new symptoms
- Symptom duration less than 1 year
- Rapid or severe weight loss (greater than 5kg)
- Odynophagia present
- Inability to pass endoscope through GOJ
- CT/EUS shows mass at GOJ
Dysphagia to solids AND liquids (100%) — from symptom onset
Common presentation.
Regurgitation of undigested food (75%) — especially nocturnal
Common presentation.
Weight loss (50%) — insidious
Common presentation.
Chest pain (40%) — retrosternal, may mimic cardiac pain
Common presentation.
Heartburn (30%) — paradoxically, from fermentation not acid
Common presentation.
5. Clinical Examination
Structured Approach
General:
- Nutritional status (BMI, muscle wasting)
- Signs of dehydration
- Respiratory status (aspiration signs)
Abdominal Examination:
- Usually unremarkable
- Epigastric mass (rare — end-stage megaoesophagus or malignancy)
Head and Neck:
- Halitosis
- Poor dentition (acid erosion less common than in GORD)
Special Tests
| Test | Technique | Positive Finding | Sensitivity/Specificity |
|---|---|---|---|
| Bedside swallow assessment | Observe water swallow | Delayed passage, regurgitation | Low sensitivity |
| Respiratory exam | Auscultation | Crackles (aspiration) | N/A |
6. Investigations
First-Line (Bedside)
- History and symptom assessment — Dysphagia pattern is key
- Nutritional assessment — Weight, BMI
Laboratory Tests
| Test | Expected Finding | Purpose |
|---|---|---|
| FBC | May show anaemia (nutritional) | Baseline |
| Albumin | May be low (malnutrition) | Nutritional status |
| Chagas serology | Positive in endemic regions | Exclude secondary achalasia |
Imaging
| Modality | Findings | Indication |
|---|---|---|
| Barium swallow | Dilated oesophagus, bird's beak narrowing at LOS, absent peristalsis | Initial investigation; characteristic appearance |
| CXR | Mediastinal widening, absent gastric air bubble, air-fluid level | May show in advanced cases |
| CT Chest/Abdomen | Dilated oesophagus, exclude GOJ mass | If pseudoachalasia suspected |
| Endoscopic ultrasound (EUS) | Exclude submucosal GOJ tumour | If pseudoachalasia suspected |
Diagnostic Criteria
High-Resolution Manometry (Gold Standard):
- Integrated Relaxation Pressure (IRP) greater than 15 mmHg (impaired LOS relaxation)
- Absent normal peristalsis (100% failed contractions or spastic pattern)
- Classified by Chicago Classification v4.0
Upper GI Endoscopy:
- May show dilated oesophagus with retained food
- Tight LOS but scope can usually pass with gentle pressure
- Essential to exclude malignancy
7. Management
Management Algorithm
Dysphagia (Solids + Liquids)
↓
┌─────────────────────────────────────────────────────┐
│ INITIAL EVALUATION │
│ - Upper GI Endoscopy (Rule out Cancer/Stricture) │
│ - Barium Swallow ("Bird's Beak" Appearance) │
└─────────────────────────────────────────────────────┘
↓
┌─────────────────────────────────────────────────────┐
│ CONFIRMATORY TEST │
│ High Resolution Manometry (HRM) │
│ (Chicago Classification v4.0 is KEY) │
└──────────────────────────┬──────────────────────────┘
↓
┌───────────┴───────────┐
↓ ↓
Risk Factors? Surgical Candidate?
(Elderly/Co-morbids) (Fit / Young / under 75)
↓ ↓
┌───────┴──────┐ ┌─────────┴─────────┐
│ Botox │ │ Choose Based │
│ (Temporary) │ │ on TYPE │
└──────────────┘ └─────────┬─────────┘
↓
┌────────────────────────┼────────────────────────┐
↓ ↓ ↓
TYPE I/II TYPE III RECURRENCE
(Classic/Comp) (Spastic) (Failed Tx)
↓ ↓ ↓
┌───────┴───────┐ ┌───────┴───────┐ ┌───────┴───────┐
│ Pneumatic │ │ POEM │ │ POEM │
│ Dilatation │ │ (Gold Std for │ │ OR │
│ OR │ │ Type III) │ │ Heller │
│ Heller Myot │ └───────────────┘ └───────────────┘
│ OR │
│ POEM │
└───────────────┘
The Eckardt Score (Severity Staging)
Score >3 indicates active disease needing treatment.
| Symptom | 0 (None) | 1 (Occasional) | 2 (Daily) | 3 (Each Meal) |
|---|---|---|---|---|
| Weight Loss | None | less than 5 kg | 5-10 kg | greater than 10 kg |
| Dysphagia | None | Occasional | Daily | Every Meal |
| Retrosternal Pain | None | Occasional | Daily | Severe/Freq |
| Regurgitation | None | Occasional | Daily | Constant |
Interventional/Surgical Management
Procedure Spotlight: POEM (Peroral Endoscopic Myotomy) The "Scarless Surgery".
- Concept: Endoscopic division of the inner circular muscle layer.
- Steps:
- Injection: Submucosa lifted with fluid in mid-oesophagus.
- Incision: Mucosal entry point created.
- Tunneling: Endoscope burrows between mucosa and muscle (submucosal tunnel) down to the stomach.
- Myotomy: The circular muscle layer (LOS) is cut from the inside.
- Closure: Mucosal entry point clipped shut.
- Pros: Excellent for Type III. No skin cuts. Quick recovery.
- Cons: High reflux rate (no fundoplication performed).
Procedure Spotlight: Laparoscopic Heller Myotomy The Traditional Gold Standard.
- Steps:
- Access: Laparoscopic ports. Mobilize distal oesophagus.
- Myotomy: Longitudinal cut of muscle layers (myotomy) on anterior oesophagus (6cm up, 2cm down onto stomach).
- Mucosa Check: Ensure mucosa is bulging but intact (air leak test).
- Dor Fundoplication: Partial (180°) anterior wrap of stomach over the myotomy site to prevent reflux and cover the exposed mucosa.
- Pros: Less reflux (due to wrap).
- Cons: Surgical risks. Not as good for Type III (myotomy length limited).
Conservative Management
- Dietary modifications: Eat slowly, small bites, drink water with meals
- Positional: Remain upright after eating; elevate head of bed
- Avoid: Large meals close to bedtime
Medical Management
| Drug Class | Drug | Dose | Notes |
|---|---|---|---|
| Calcium Channel Blocker | Nifedipine | 10-30mg sublingual before meals | Modest benefit; side effects limit use |
| Nitrate | Isosorbide dinitrate | 5-10mg sublingual before meals | Modest benefit; headache common |
| Botulinum Toxin | Botox injection (endoscopic) | 100 units into LOS | Temporary (3-12 months); bridge therapy |
Note: Medical therapy is rarely effective long-term; used as bridge or for those unfit for definitive treatment
Interventional/Surgical Management
Definitive Treatment Options:
| Procedure | Technique | Efficacy | Complications |
|---|---|---|---|
| Pneumatic Dilation | Endoscopic balloon dilation (30-40mm) | 70-90% initial; ~50% at 5y | Perforation 2-5%; repeat sessions often needed |
| Laparoscopic Heller Myotomy | Surgical division of LOS muscle + Dor fundoplication | 85-95% at 5y | GORD 10-30%; perforation 1% |
| POEM | Peroral endoscopic myotomy | 90-95% at 2y | GORD 20-50%; perforation rare |
Treatment Selection:
| Scenario | Preferred Treatment |
|---|---|
| Type II achalasia | Any treatment effective; POEM or myotomy preferred |
| Type I achalasia | Heller myotomy or POEM |
| Type III achalasia | POEM (longer myotomy possible) |
| Elderly/unfit | Pneumatic dilation or Botox |
| Failed prior intervention | POEM or surgical revision |
Disposition
- Outpatient: Diagnosis and treatment planning
- Admit if: Severe malnutrition, aspiration pneumonia, need for urgent intervention
- Follow-up: Post-procedure review at 6 weeks; surveillance endoscopy at intervals
8. Complications
Immediate (Minutes-Hours)
| Complication | Incidence | Presentation | Management |
|---|---|---|---|
| Perforation (dilation/POEM) | 1-5% | Chest pain, fever, crepitus | CT; surgical/endoscopic repair |
| Bleeding | Rare | Haematemesis | Endoscopic haemostasis |
Early (Days-Weeks)
- Aspiration pneumonia: Presents with fever, cough, CXR infiltrates
- Post-procedure GORD: Especially after POEM; manage with PPI
Late (Months-Years)
- Recurrence of dysphagia: 20-50% at 10 years; may need repeat intervention
- GORD: Common post-myotomy/POEM; requires long-term PPI
- Oesophageal squamous cell carcinoma: 10-50x increased risk; surveillance advised
- Megaoesophagus: End-stage; may require oesophagectomy
9. Prognosis & Outcomes
Natural History
- Progressive dysphagia without treatment
- Oesophageal dilation and stasis
- Increased aspiration and malnutrition risk
- Increased oesophageal cancer risk over time
Outcomes with Treatment
| Variable | Outcome |
|---|---|
| Symptom relief (myotomy/POEM) | 90-95% at 2 years |
| Symptom relief (pneumatic dilation) | 70-90% initial; 50% at 5 years |
| Need for reintervention | 20-30% at 10 years |
| Post-procedure GORD | 10-50% (higher with POEM) |
Prognostic Factors
Good Prognosis:
- Type II achalasia (best treatment response)
- Younger age at treatment
- Less oesophageal dilation at baseline
- Early intervention
Poor Prognosis:
- Type III achalasia (poorest treatment response)
- Sigmoid megaoesophagus (may need oesophagectomy)
- Delayed diagnosis
- Multiple failed interventions
10. Evidence & Guidelines
Key Guidelines
- ACG Clinical Guideline: Achalasia (Vaezi et al., 2020) — American College of Gastroenterology. Recommends manometry for diagnosis; Heller myotomy, POEM, or pneumatic dilation as primary treatments. ACG Guidelines
- UEG Guidelines on Achalasia (2020) — United European Gastroenterology. Comprehensive guidance on diagnosis and management.
- ESGE Guideline on POEM (2022) — European Society of Gastrointestinal Endoscopy. POEM as effective alternative to Heller myotomy.
Landmark Trials
POET Trial (Werner et al., 2019) — POEM vs Pneumatic Dilation
- 133 patients randomised
- Key finding: POEM superior to pneumatic dilation at 2 years (92% vs 54% treatment success)
- Clinical Impact: Established POEM as preferred over pneumatic dilation
European Achalasia Trial (Boeckxstaens et al., 2011) — Pneumatic Dilation vs Heller Myotomy
- 201 patients randomised
- Key finding: Equivalent efficacy at 2 years (86% vs 90%)
- Clinical Impact: Validated pneumatic dilation as alternative to surgery
Meta-analyses on POEM (2020) — Pooled data
- Key finding: POEM has high efficacy (greater than 90%) but higher GORD rates (20-50%) than Heller + fundoplication
- Clinical Impact: Consider fundoplication for GORD prevention
Evidence Strength
| Intervention | Level | Key Evidence |
|---|---|---|
| Manometry for diagnosis | 1a | Multi-society guidelines |
| POEM vs Pneumatic Dilation | 1b | POET Trial |
| Heller myotomy | 1b | European Achalasia Trial |
| Botox (temporary) | 2a | Systematic reviews |
11. Patient/Layperson Explanation
What is Achalasia?
Achalasia is a condition where the valve at the bottom of your food pipe (oesophagus) does not open properly, and the muscles of the food pipe do not push food down as they should. This happens because the nerves that control these muscles have been damaged. As a result, food gets stuck and you have difficulty swallowing.
Why does it matter?
Without treatment, food and drink will build up in your food pipe, making swallowing more and more difficult. You may lose weight because you cannot eat enough. Food that stays in the food pipe can sometimes go into your lungs (aspiration), which can cause chest infections.
How is it treated?
The goal of treatment is to open the tight valve so food can pass into your stomach. There are several options:
- Keyhole surgery (Heller Myotomy): The surgeon cuts the muscle of the valve through small cuts in your tummy. Most people have a partial wrap of the stomach added to prevent acid reflux.
- POEM (Peroral Endoscopic Myotomy): A newer procedure where the surgeon cuts the valve muscle using a camera passed down your throat. No cuts on your skin.
- Balloon dilation (Pneumatic Dilation): A balloon is passed down to stretch the valve. May need repeating.
- Botox injection: A temporary option for those who cannot have surgery. Lasts 3-12 months.
What to expect
- After successful treatment, most people can eat normally again
- You may need to take medication for acid reflux long-term
- The condition can sometimes come back, and you may need further treatment
- You will need occasional check-ups with a camera test (endoscopy) because there is a small increased risk of developing oesophageal cancer over time
When to seek help
See your doctor or go to hospital if:
- You cannot swallow anything, including liquids or saliva
- You have severe chest pain
- You cough or choke frequently when eating
- You develop a fever or breathing problems
12. References
Primary Guidelines
- Vaezi MF, et al. ACG Clinical Guideline: Diagnosis and Management of Achalasia. Am J Gastroenterol. 2020;115(9):1393-1411. PMID: 32773454
- Oude Nijhuis RAB, et al. European Guideline on Achalasia: United European Gastroenterology and European Society of Neurogastroenterology and Motility Recommendations. United European Gastroenterol J. 2020;8(1):13-33. PMID: 32213003
Key Trials
- Werner YB, et al. Endoscopic or surgical myotomy in patients with idiopathic achalasia (POET Trial). N Engl J Med. 2019;381(23):2219-2229. PMID: 31800987
- Boeckxstaens GE, et al. Pneumatic dilation versus laparoscopic Heller's myotomy for idiopathic achalasia. N Engl J Med. 2011;364(19):1807-1816. PMID: 21561346
- Inoue H, et al. Peroral endoscopic myotomy (POEM) for esophageal achalasia. Endoscopy. 2010;42(4):265-271. PMID: 20354937
Further Resources
- Guts UK Charity: gutscharity.org.uk
- Achalasia Action: achalasiaaction.org
- CORE (Digestive Disorders Foundation): corecharity.org.uk
13. Examination Focus
The "Dysphagia" Station
1. The History (Crucial Differentiators)
- Solids vs Liquids:
- Solids then Liquids = Mechanical Stricture (Cancer/Peptic).
- Solids AND Liquids together = Motility Disorder (Achalasia).
- Timeframe:
- Short (less than 6m) + Wt Loss = Cancer (Pseudoachalasia).
- Long (>2y) = Achalasia.
- Regurgitation:
- Fresh/Acidic = GORD.
- Undigested/Bland/Nocturnal = Achalasia (Food sitting in the pouch).
2. Interpretation: Barium Swallow
- The Sign: "Bird's Beak" or "Rat's Tail".
- Description: Smooth, symmetric tapering of the distal oesophagus. Dilated proximal oesophagus (Sigmoid shape if severe). Absence of gastric air bubble.
3. Interpretation: Manometry (High Res)
- Type I: No pressure waves (Dead tube).
- Type II: Pan-oesophageal pressurization (Whole tube squeezes at once). Best prognosis.
- Type III: Spastic contractions (Tube goes crazy). Worst prognosis.
Viva Questions:
- Q: What is the Gold Standard for Diagnosis?
- A: High Resolution Manometry (HRM).
- Q: Why do patients get recurrent pneumonia?
- A: Silent aspiration of undigested food accumulating in the dilated oesophagus, especially at night when supine.
- Q: Explain Pseudoachalasia.
- A: A tumour at the GOJ (gastric cardia) infiltrating the myenteric plexus, dissecting the nerves and mimicking the manometry findings of achalasia. Always scope to rule this out!
- Q: What is the main complication of Heller Myotomy?
- A: Reflux (GORD). This is why we add a Fundoplication (Dor/Toupet).
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Consult a gastroenterologist or upper GI surgeon for achalasia management.